I've said this before and I'll say it again.  I've been fat and thin and everywhere in between.  There's no way in hell she was 145 in that pic.  I'd go with at least 170, if not more.

PS, I agree with what you said - why doesn't she just own up to it?  She's the one who is making her weight an issue, the least she could do is tell the truth about it (especially if she's supposedly trying to help people lose weight).  Hell, be proud you've gone from 200 to 170 (or whatever).